It is known that a variety of furanone compounds possessing anti-fungal and antimicrobial properties can be isolated from red marine algae Delisea fimbriata, Delisea elegans and Delisea pulchra (Reichelt and Borowitzka (1984) Hydrobiologia 116: 158–168). When first isolated, it was thought that these compounds may be suitable as antimicrobial agents for use in animals including humans. Unfortunately, it was found that most if not all of these naturally occurring compounds were toxic to animal cells at the concentrations required to inhibit microorganisms and therefore unsuitable for many veterinary and medical applications.
Gram positive bacteria are a major problem in hospitals, on skin, in the dental area, for heart transplants, catheters, and other biomedical implants. Unfortunately, not all antimicrobial agents are active against Gram positive bacteria. Gram positive bacteria are also present in domestic areas like bathrooms, toilets and kitchens and can also cause a disease hazard for these sources. Accordingly, there is a need for more agents that are suitable to inhibit or kill these types of microorganisms in many varied situations including domestic, veterinary and medical applications.
The present inventors have now made the surprising finding that new synthetically produced furanone compounds have inhibitory activity against Gram positive bacteria without having corresponding deleterious activity against animal cells previously reported to be the case with naturally occurring furanones.